The yak (Bos Grunniens) is a type of long haired bovine that is commonly found in the Himalayas. It has adapted in many ways to live in this harsh environment and these adaptations are what make it so interesting.
Structural adaptations
I will be examining two structural adaptations of the yak. The first is the ones that allow the yak to survive in the high altitude. In order to do so, the yak has an extra pair of ribs to allow for extra lung capacity. The yak also has a long thick coat to deal with the cold temperatures. Their coat consists of an inner layer made of warm soft down and long soft outer hair. They also have an undercarriage of dense long hair that can hang down and touch the ground sometimes. Yak hair has always been used by Tibetan people because of its warmth and length. The outer hair is often used as a cover for huts and wove into mats. The soft inner down is extremely warm and can be woven into blankets and clothing. It is comparable to cashmere.
Another way that the yak survives in the cold temperatures is that it gains a lot of weight during the freezing winter months. They put on a good layer of fat right before winter which provides an energy reserve and also acts as insulation.
Behavioral Adaptations
Yaks tend to move in herds of about 10-30. They prefer to stay in large herds for protection, especially against wolves (wolves used to be a threat to wild yak, but now only threaten domestic yak. But domestic yak are the same species as their wild counterparts). The yak is also easily excited and has quick reflexes. They panic easily when startled and run away. This helps then escape from predators, however if they run off on their own away from the herd they can be taken down on their own. They are vigilant to attack from other animals and if they are threatened they have been known to attack and kill predators such as wolves. They do so by charging them with their largehorns.
Fig 3: A plateau where Yaks can live
Physiological Adaptations
THe yak has a few Physiological adaptations that allow it to survive in the wild. The first, and most prominent, is the increased amount of red blood cells that the yak has. These extra red blood cells allow oxygen to move through the yaks system more easily and help to surv
ive in high altitude. The second is the fact that the Yak has a slower digestive system that most other Bovines. The longer residence of food in its system means that the yak is able to survi
ve on lower quality forage. This is vital to the yaks survival as there is not a lot of grass at the high altitudes where wild Yak live. THey can also survive on the long grass that sticks up through the snow in the winter months, which is also vital as otherwise they would have nothing to eat during the freezing winters.
How did these adaptations come about?
These adaptations almost certainly came about because of the harsh climate their ancestors lived in. Because of survival of the fittest, the ones with the thickest coats would have survived the cold winters to pass on their genes. Also, the ones that reacted quickly to danger would have survived and the others would have died out. The same is true for the ancestors that had more red blood cells. All of these contributed to the Yaks existence. Of course, these would have taken thousands of years to amplify themselves to the point where the Yak became the highly specialized animal it is today.
Habitat
Wild yak used to be common and well spread around the entire Tibetan plateau that was north of the
Himalayas. They can now only be found in remote areas of the Tibetan plateau and the highlands adjacent to them.
The can also be found in the Gansu province of china and afew have been seenin the Chan
Fig 3: A map of Tibet showing the distribution of the Yak
g Chenmo valley of Ladakh, which is in India (east Kashmir). The weather in these regions is harsh and the yak can survive in temperatures up to minus 40 degrees celcius. These areas are also normally higher then 4000 meters above sea level.
The yak (Bos Grunniens) is a type of long haired bovine that is commonly found in the Himalayas. It has adapted in many ways to live in this harsh environment and these adaptations are what make it so interesting.
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Family: Bovidae
Genus: Bos
Species: B.Grunniens
Binomial Name: Bos Grunniens
Structural adaptations
I will be examining two structural adaptations of the yak. The first is the ones that allow the yak to survive in the high altitude. In order to do so, the yak has an extra pair of ribs to allow for extra lung capacity. The yak also has a long thick coat to deal with the cold temperatures. Their coat consists of an inner layer made of warm soft down and long soft outer hair. They also have an undercarriage of dense long hair that can hang down and touch the ground sometimes. Yak hair has always been used by Tibetan people because of its warmth and length. The outer hair is often used as a cover for huts and wove into mats. The soft inner down is extremely warm and can be woven into blankets and clothing. It is comparable to cashmere.
Another way that the yak survives in the cold temperatures is that it gains a lot of weight during the freezing winter months. They put on a good layer of fat right before winter which provides an energy reserve and also acts as insulation.
Behavioral Adaptations
Yaks tend to move in herds of about 10-30. They prefer to stay in large herds for protection, especially against wolves (wolves used to be a threat to wild yak, but now only threaten domestic yak. But domestic yak are the same species as their wild counterparts). The yak is also easily excited and has quick reflexes. They panic easily when startled and run away. This helps then escape from predators, however if they run off on their own away from the herd they can be taken down on their own. They are vigilant to attack from other animals and if they are threatened they have been known to attack and kill predators such as wolves. They do so by charging them with their largehorns.
Physiological Adaptations
THe yak has a few Physiological adaptations that allow it to survive in the wild. The first, and most prominent, is the increased amount of red blood cells that the yak has. These extra red blood cells allow oxygen to move through the yaks system more easily and help to surv
ive in high altitude. The second is the fact that the Yak has a slower digestive system that most other Bovines. The longer residence of food in its system means that the yak is able to survi
ve on lower quality forage. This is vital to the yaks survival as there is not a lot of grass at the high altitudes where wild Yak live. THey can also survive on the long grass that sticks up through the snow in the winter months, which is also vital as otherwise they would have nothing to eat during the freezing winters.
How did these adaptations come about?
These adaptations almost certainly came about because of the harsh climate their ancestors lived in. Because of survival of the fittest, the ones with the thickest coats would have survived the cold winters to pass on their genes. Also, the ones that reacted quickly to danger would have survived and the others would have died out. The same is true for the ancestors that had more red blood cells. All of these contributed to the Yaks existence. Of course, these would have taken thousands of years to amplify themselves to the point where the Yak became the highly specialized animal it is today.
Habitat
Wild yak used to be common and well spread around the entire Tibetan plateau that was north of the
Himalayas. They can now only be found in remote areas of the Tibetan plateau and the highlands adjacent to them.
The can also be found in the Gansu province of china and afew have been seenin the Chan
Bibliography
The Yak. (2010, June 11). Retrieved July 2, 2010, from http://en.wikipedia.org/wiki/Yak
Animal Info. (2005, March 5). Bos Grunniens. Retrieved July 1, 2010, from http://www.animalinfo.org/species/artiperi/bos_mutu.htm
Huffman, B. (2004, March 23). Bos Grunniens. Retrieved June 9, 2010, from http://www.ultimateungulate.com/artiodactyla/bos_grunniens.html
The Ancient Yak (Bos Primigenius)
The Future Yak (Bos Prodigiosus)